I have the chance to buy a pair of 50+ year old ramshorn manifolds for my 292. One of the manifolds has been dropped and the ear for the end mounting bolt broke off. If I have it repaired by an expert welder what are my chances that the weld in 50 year old cast iron will be a permanent repair ? I know little about welding, is this an easy repair or a roll of the dice ? Thanks, Mark
If your welder actually knows what he's doing, and has experience successfully welding cast iron, it should be a permanent repair.
Thank you Mike, I remembered reading somewhere that old exhaust manifolds were hard to repair because of the high carbon content or the constant heating and cooling making the metal brittle, or something like that. For the price I can afford to try and have it repaired. Thanks again, Mark
There are lots of variables in castings - from tin content to porosity - so get a similiar piece for him to practice and dial in the welding.
It's very doable. I welded my cast iron exhaust manifold as follow: 1. "V" edges using a file. 2. Clamp both pieces together in proper alignment on a flat steel surface so pieces are "flush". 3. Pre heat piece to about 450 degrees. 4. Arc weld using high nickle content rod. 5. Immediately tap weld with a ball peen hammer or chipping hammer to relieve stresses while it is cooling down. 6. File to make ear even with flange, if needed. Other folks may have diferent techniques and I do not purport to be an expert.
Send it to me, I will give it another 50 years of service for you. One of the things that you have to watch when it is repaired is that the flange lays flat. if it does not lay flat, or true is actually a better term, it will be easier to crack when it is torqued down.
Pretty Impressive. 19Fordy are you a welder by chance or a restorer? That method is damn near spot on of how I was taught.
Thanks for the kind words. I learned how to weld (a little) as a high school shop teacher and I did restore my avatar car. I am not a professional at either.
My Dad used to weld C.I. a lot, furnace grates for the local Amish folks. He would pre-heat on a bed of charcoal also get it about 400/450 degrees, checking it with a temple stick, stick weld with a high nickel rod, but then cover the whole deal in a mound of dry sand, let it sit until it was cool enough, like the next day, to lift out with your hand.
I agree with clamping it to a heavy flat surface. File or grind a big chamfer, heat much more than the weld area, then gas weld using cast iron rod and Lewis Lye for a flux. Play the heat for fifteen minutes or so to cool it very slowly. Leave it clamped overnight to cool completly.
they make rod now just for welding cast, its big bucks but it works better than high nickel for steel.
yea we call it zoom rod, an armature could get a good weld on cast iron with it. It was about 8 bucks a stick the last I bought. I still use Ni Rod if I don't have zoom rod, I don't have any problem with either one. granted no one told me that it couldn't be done or that it was majic 40 years ago when I first tried it.
I thank you all for your thoughts. I can do wonderous things with wood, when it comes to welding metal, me and my "suzi homemaker" buzzbox can get a project together just well enough to get it to a pro welder. Thanks, Mark
Unless there is some great sentimental value in the old manifold, a pro welder will probably charge you more to fix it than you can buy a new repop. Dorman and others sell new onew for about $50.
You're getting good advice on welding -especially keeping that mating surface square. Use exhaust manifold gaskets for a little insurance with welded manifold (original was manifold to head surface. Torque and your done. RT
You're thinking SBC, not Y-block Ford. They do, however, repop them for Y-blocks....but not for 50 bucks a piece.
Dont let anyone tell you something cant be done untill you tried it yourself. I welded 48 year old cast iron manifold ear back on and patched a gaping crack with my little flux core wire feed welder. I cleaned and heated up the area then turned the machine on full blast and away I went. It held together for over a year Before I changed the motor, now those manifolds are in the s**** pile. Everyone said it would not work, well everyone was wrong. "some times it pays to be poor"
Some parts weld better than others. Regardless of what anyone tells you, an iron part welded using conventional methods can never be as good as new. If things go well the weld will be adequate, if not the part will crack again.
ill check and see what i have what size and side is it i have a couple hundred layin around ill give you one if there is one umugst them im going wendsday let me know
Going back to my short navy career as a shipfitter3 my boss instructed us how to weld a broken vice. He used silversolder instead of br***. It had a very hi tensil strength and he said that the cast iron would break before the silversolder, [also brazing]. As I recall he demonstrated it by breaking the vice again,which showed it had broke the cast iron. He had stacked a pile of bricks to make a small oven for welding and cool down. Just food for thought on welding cast iron.
Well, maybe. I can't dispute anything you posted, but there is a little more to it. It's also important to realize that impact strength does not necessarily parallel differences in tensile strength. Grey iron is fairly weak and relatively brittle. Only cheap weak vises are made of grey iron. A good silver solder/braze joint on grey iron can be stronger than the part itself. Although it varies with the part and the manufacturer, most auto parts are not made of straight grey iron. The iron is alloyed and or processed in one way or another to make it better. A decent vise could be made from malleable iron, but that's not common. The strongest silver solder/braze alloy, with the brazing done under ideal conditions(like in a furnace), will produce a repair that is approximately as strong as malleable iron. Good vises(and many modern auto castings like steering arms, spindles, hubs) are made of ductile/nodular iron. No matter what silver solder/braze is used, and no matter how the joint is done, ductile iron is significantly stronger than the joint can be. Do any of these joints outside a controlled environment, like free-hand with a torch, and the strength of the joint tends to go down, and the likelihood of weakening the party itself goes up.
I have had several manifolds welded by co workers who would fall into the expert category and the only differences from this post is that he peens the weld and the surrounding area with an air chisel set very low in between each bead (no longer than 1/2") and wraps it in an asbestos blanket overnight (burying it in kitty litter or sand will work too). His preferred rod is UTP FN-85.
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